Our evaluation of Biobeat’s ABPM technologies involves two tracks: clinical and decision-making. The first focuses on diagnosis, treatment, and efficacy, while the second centers on doctor-patient decision-making. I reached out to renowned thoracic surgeon and CEO of HPC International, Dr. Hilton Hudson, for insights on ABPM’s clinical implications for diagnosing, treating, and managing hypertension. This post reflects our collaboration.
Starting with the basics, blood pressure is the force exerted by circulating blood on the walls of blood vessels. Systemic blood pressure is generated when the left side of the heart contracts (systole) and pushes oxygenated blood through the aortic valve into the Aorta artery and its branches to profuse organs and tissues. Then the left ventricle relaxes (diastole), and pressure drops, which causes the aortic valve to close. The Aorta decompresses or recoils, which pushes blood into the aortic branches at a lower pressure to sustain blood flow to the organs and tissues.
These are the two blood pressure numbers reported by legacy pressure monitors, including ambulatory BP systems, along with heart rate. Older technologies cannot measure and distinguish the contributions of BP’s components, Cardiac Output (CO), and Systemic Vascular Resistance (SVR): BP = CO x SVR. CO is the volume of blood pumped by the heart each minute and is determined by Stroke Volume (SV), the amount of blood pushed out by the heart with each compression of the left ventricle, and Heart Rate (HR), i.e., the number of compressions per minute.
Doctors diagnosing and developing hypertension treatment strategies have had to form hypotheses based on limited information. As a result, pharmacological treatments of blood pressure have broadly included multiple drugs that target Cardiac Output and Systemic Vascular Resistance. Doctors are similarly blind when treatments prove ineffective and are left with iterative trial-and-error strategies.
By contrast, clinicians using Biobeat’s ABPM are fully aware of the relative contributions of CO, SVR, and SV in their patients’ BP. They can leverage the information in formulating targeted treatment strategies, validating individual patient responses, and adjusting treatments. These considerations are particularly important when patient-specific factors influence drug and dosage selection and force doctors to consider other drug combinations. We will discuss these issues and their implications in our upcoming posts on the influence of treatment strategies and selection on patient compliance.
The advantages outlined above become more pronounced when ABPM’s other measures are considered. That’s the subject of our next post.
Image and references
Image courtesy of Biobeat